Light-emitting diode and manufacturing method therefor

Abstract

A light-emitting diode and a manufacturing method therefor are disclosed. The light-emitting diode comprises: a first conductive semiconductor layer; at least two light-emitting units arranged by being spaced from each other on the first conductive semiconductor layer, respectively including an active layer and a second conductive semiconductor layer, and including one or more contact holes through which the first conductive semiconductor layer is partially exposed; an additional contact area located between the light-emitting units; a second electrode making ohmic contact with the second conductive semiconductor layer; a lower insulation layer; and a first electrode making ohmic contact with the first conductive semiconductor layer through the contact holes of each of the light-emitting units and the additional contact area.

The invention claimed is: 
     
       1. A light emitting diode comprising:
 a first conductive type semiconductor layer; 
 at least two light emitting units disposed on the first conductive type semiconductor layer to be spaced apart from each other, each comprising an active layer, a second conductive type semiconductor layer, and at least one contact hole formed through the second conductive type semiconductor layer and the active layer so as to expose a portion of the first conductive type semiconductor layer; 
 an additional contact region disposed between the light emitting units and partially exposing the first conductive type semiconductor layer; 
 a first electrode forming ohmic contact with the first conductive type semiconductor layer through the contact hole of each light emitting unit and the additional contact region; 
 a second electrode disposed on each of the light emitting units and forming ohmic contact with the second conductive type semiconductor layer; and 
 a lower insulation layer covering a side surface of the first conductive type semiconductor layer, the light emitting units, and the second electrode, 
 wherein the lower insulation layer is shaped to include a first opening exposing the contact hole and the additional contact region and a second opening partially exposing the second electrode, the first and second electrode being insulated from each other. 
 
     
     
       2. The light emitting diode according to  claim 1 , wherein the light emitting diode comprises at least four light emitting units and the additional contact region is disposed in a region surrounded by the at least four light emitting units. 
     
     
       3. The light emitting diode according to  claim 2 , wherein the additional contact region is disposed in a region in which corners of each of the at least four light emitting units meet. 
     
     
       4. The light emitting diode according to  claim 2 , wherein distances from a center of the additional contact region to centers of the at least four light emitting units are the same. 
     
     
       5. The light emitting diode according to of  claim 1 , wherein the contact hole is disposed in a central region of each of the light emitting units. 
     
     
       6. The light emitting diode according to  claim 1 , further comprising:
 one or more connection layers electrically connecting the second electrode disposed on one of the light emitting units to the second electrode disposed on another light emitting unit adjacent to the one light emitting unit. 
 
     
     
       7. The light emitting diode according to  claim 1 , wherein the first electrode covers at least part of the lower insulation layer and contacts the first conductive type semiconductor layer through the first opening. 
     
     
       8. The light emitting diode according to  claim 7 , wherein the first electrode further covers the first conductive type semiconductor layer and side surfaces of the light emitting units and is insulated by the lower insulation layer. 
     
     
       9. The light emitting diode according to  claim 1 , further comprising:
 an upper insulation layer at least partially covering the first electrode, 
 wherein the upper insulation layer comprises a third opening partially exposing the first electrode and a fourth opening partially exposing the second electrode. 
 
     
     
       10. The light emitting diode according to  claim 9 , further comprising:
 a first pad disposed on the third opening and electrically connected to the first electrode; and 
 a second pad disposed on the fourth opening and electrically connected to the second electrode. 
 
     
     
       11. The light emitting diode according to  claim 10 , further comprising:
 a heat dissipation pad disposed on the upper insulation layer. 
 
     
     
       12. The light emitting diode according to  claim 11 , wherein the heat dissipation pad is disposed between the first pad and the second pad. 
     
     
       13. A method of manufacturing a light emitting diode, comprising:
 forming a first conductive type semiconductor layer, an active layer and a second conductive type semiconductor layer on a substrate; 
 forming at least two light emitting units each comprising the second conductive type semiconductor layer, the active layer and contact holes by partially removing the second conductive type semiconductor layer and the active layer; 
 forming an additional contact region disposed in a region between the light emitting units; 
 forming a second electrode on each of the light emitting units so as to form ohmic contact with the second conductive type semiconductor layer; 
 forming a lower insulation layer covering a side surface of the first conductive type semiconductor layer, the light emitting units, and the second electrodes; and 
 forming a first electrode forming ohmic contact with the first conductive type semiconductor layer through the contact holes and the additional contact region, 
 wherein the contact holes are formed through the second conductive type semiconductor layer and the active layer so as to expose a portion of the first conductive type semiconductor layer, the first conductive type semiconductor layer is exposed to a lower side of the additional contact region, and the lower insulation layer comprises first openings exposing the contact holes and the additional contact region, and second openings partially exposing the second electrodes. 
 
     
     
       14. The method of manufacturing a light emitting diode according to  claim 13 , wherein the light emitting units comprise at least four light emitting units, and the additional contact region is disposed in a region surrounded by the at least four light emitting units. 
     
     
       15. The method of manufacturing a light emitting diode according to  claim 14 , wherein the additional contact region is disposed in a region in which corners of each of the at least four light emitting units are disposed. 
     
     
       16. The method of manufacturing a light emitting diode according to  claim 13 , further comprising:
 forming one or more connection layers electrically connecting the second electrode disposed on one of the light emitting units to the second electrode disposed on another light emitting unit adjacent to the one light emitting unit. 
 
     
     
       17. The method of manufacturing a light emitting diode according to  claim 16 , wherein the connection layers are formed simultaneously with the first electrode. 
     
     
       18. The method of manufacturing a light emitting diode according to  claim 13 , wherein the forming of the first electrode comprises filling the first openings with the first electrode such that the first electrode contacts the first conductive type semiconductor layer through the first openings. 
     
     
       19. The method of manufacturing a light emitting diode according to  claim 13 , further comprising:
 forming an upper insulation layer at least partially covering the first electrode after formation of the first electrode, 
 wherein the upper insulation layer comprises a third opening partially exposing the first electrode and a fourth opening partially exposing the second electrode. 
 
     
     
       20. The method of manufacturing a light emitting diode according to  claim 19 , further comprising:
 forming a first pad on the third opening so as to be electrically connected to the first electrode and a second pad on the fourth opening so as to be electrically connected to the second electrode. 
 
     
     
       21. The method of manufacturing a light emitting diode according to  claim 20 , further comprising: forming a heat dissipation pad on the upper insulation layer. 
     
     
       22. The method of manufacturing a light emitting diode according to  claim 21 , wherein the first pad, the second pad and the heat dissipation pad are formed at the same time. 
     
     
       23. A light emitting diode comprising:
 a light emitting structure comprising a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer, the light emitting structure comprising one or more mesas disposed on the first conductive type semiconductor layer to be spaced apart from each other and each comprising the active layer and the second conductive type semiconductor layer and having at least one contact hole formed through the second conductive type semiconductor layer and the active layer so as to expose a portion of the first conductive type semiconductor layer; 
 a first electrode forming ohmic contact with the first conductive type semiconductor layer through the contact holes of the one or more mesas; 
 a current spreading layer disposed on the one or more mesas and forming ohmic contact with the second conductive type semiconductor layer; 
 a second electrode disposed on the current spreading layer; and 
 an insulation layer covering the light emitting structure and the current spreading layer, and comprising openings partially exposing the first and second electrodes, 
 wherein each of the contact holes comprise a plurality of main contact holes spaced apart from one another and secondary contact holes connecting the main contact holes to each other and having a smaller width than the main contact holes. 
 
     
     
       24. The light emitting diode according to  claim 23 , further comprising:
 a current blocking layer disposed under the current spreading layer, 
 wherein the current blocking layer is disposed below the second electrode so as to correspond to a location of the second electrode. 
 
     
     
       25. The light emitting diode according to  claim 23 , wherein the current spreading layer comprises a conductive oxide. 
     
     
       26. The light emitting diode according to  claim 25 , wherein the current spreading layer comprises a lower current spreading layer and an upper current spreading layer disposed on the lower current spreading layer. 
     
     
       27. The light emitting diode according to  claim 25 , wherein the current spreading layer includes a conductive oxide doped with a metallic dopant. 
     
     
       28. The light emitting diode according to  claim 23 , further comprising:
 a first pad and a second pad disposed on the insulation layer and electrically connected to the first electrode and the second electrode, respectively, 
 the first and second pad being spaced apart from each other. 
 
     
     
       29. The light emitting diode according to  claim 28 , wherein the first electrode comprises:
 a first ohmic contact electrode disposed under the first pad; 
 a second ohmic contact electrode comprising a main electrode disposed under the first pad and an extension electrode extending from the main electrode to a portion under a region between the first pad and the second pad; and 
 a third ohmic contact electrode disposed under the first pad and forming ohmic contact with an additional contact region. 
 
     
     
       30. The light emitting diode according to  claim 29 , wherein the main electrode of the second ohmic contact electrode is disposed in the main contact holes and the extension electrode of the second ohmic contact electrode is disposed in the main contact holes and the secondary contact holes. 
     
     
       31. The light emitting diode according to  claim 30 , wherein a portion of the extension electrode disposed in the main contact holes has a greater width than a portion of the extension electrode disposed in the secondary contact holes and is disposed under the region between the first pad and the second pad. 
     
     
       32. The light emitting diode according to  claim 29 , wherein the extension electrode of the second ohmic contact electrode is covered by the insulation layer. 
     
     
       33. The light emitting diode according to  claim 28 , wherein the second electrode comprises:
 a first connection electrode disposed under the second pad; and 
 a second connection electrode comprising a main electrode disposed under the second pad and an extension electrode extending from the main electrode towards the first pad. 
 
     
     
       34. The light emitting diode according to  claim 33 , wherein the extension electrode of the second connection electrode extends to a portion under a region between the first pad and the second pad. 
     
     
       35. The light emitting diode according to  claim 34 , wherein the extension electrode of the second connection electrode further extends to a region under the first pad. 
     
     
       36. The light emitting diode according to  claim 33 , wherein the extension electrode has a smaller width than the main electrode. 
     
     
       37. The light emitting diode according to  claim 33 , wherein the extension electrode is covered by the insulation layer. 
     
     
       38. The light emitting diode according to  claim 23 , wherein the one or more mesas comprise a plurality of mesas; the light emitting structure is disposed between the plurality of mesas and further comprises an additional contact region partially exposing the first conductive type semiconductor layer; and the first electrode disposed on the additional contact region is exposed through the openings of the insulation layer. 
     
     
       39. The light emitting diode according to  claim 23 , wherein the insulation layer comprises:
 a lower insulation layer; and 
 an upper insulation layer disposed on the lower insulation layer. 
 
     
     
       40. The light emitting diode according to  claim 39 , wherein the lower insulation layer has a greater thickness than the upper insulation layer, and the upper insulation layer comprises a distributed Bragg reflector. 
     
     
       41. The light emitting diode according to  claim 40 , wherein the lower insulation layer includes SiO 2  and has a thickness of 0.2 μm to 1.0 μm, and the upper insulation layer has a stack structure in which TiO 2 /SiO 2  layers are alternately stacked one above another. 
     
     
       42. The light emitting diode according to  claim 39 , wherein at least part of the first electrode and the second electrode covers an upper surface of the lower insulation layer around the openings of the lower insulation layer to be interposed between the lower insulation layer and the upper insulation layer.